Development of an error correction system in teletext for PAL-TV signals

There are four teletext systems, systems A to D, which are recommended by the CCIR. System D, developed in Japan, has adopted a powerful error correction system, known as BEST (burst and random error correction system for teletext), for NTSC-TV systems. A novel transmission system, in which BEST can be multiplexed with the PAL-TV signal, has been invented, as a teletext for China which uses Chinese characters, while developing devices for transmission and reception. Using these devices, indoor and outdoor experiments were carried out in cooperation with the Ministry of Radio, Film and TV of China to compare BEST with WST (world system teletext). The author describes the outline of BEST for the PAL-TV signals and the results of the experiments comparing it with WST